In typical fuel injection engine systems, it is vital to know the position of each cylinder in order to properly time fuel injection. In conventional locomotive diesel engines, each cylinder performs a power stroke and an exhaust stroke. The crank wheel which is engaged to the crankshaft and responsive thereto performs two revolutions in completing a power stroke and an exhaust stroke for a given cylinder. The engine control process that governs fuel injection into a cylinder during a power stroke must obtain information from a camshaft (which performs one revolution for every two revolutions of the crankshaft) in order to properly determine whether a given cylinder is at its power stroke or exhaust stroke, i.e., in the first or second crank revolution. This type of operation is commonly called a four-stroke mode.
For some engines, the installation of a cam sensor is difficult and presents quality control issues during assembly. The performance of the cam sensor is related to its placement in the engine. Space constraints influence the positioning of the cam sensor and result in cam sensors being located at areas of excessive acceleration. It is generally recognized in the field of engine manufacturing and assembly that utilizing the least number of parts possible to achieve a desired function increases reliability and reduces costs. If one could eliminate the cam sensor, one could also eliminate machining done on the cam sensor cover and timing wheel. A fuel injected engine capable of starting and running without the need of a cam signal is desired.